Add logging to plugin fetch treatment method (#61)

* Add logging to plugin fetch treatment method

* Regroup dependencies in go mod file

plugins/turing/go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/caraml-dev/xp/treatment-service v0.0.0
 	github.com/go-playground/validator/v10 v10.11.1
 	github.com/gojek/mlp v1.5.3
+	github.com/google/uuid v1.3.0
 	github.com/pkg/errors v0.9.1
 	github.com/prometheus/client_golang v1.12.2 // indirect
 	github.com/stretchr/testify v1.8.0
@@ -61,7 +62,6 @@ require (
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/go-cmp v0.5.9 // indirect
-	github.com/google/uuid v1.3.0 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.2.0 // indirect
 	github.com/googleapis/gax-go/v2 v2.6.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.11.2 // indirect

plugins/turing/runner/experiment_runner.go

@@ -19,7 +19,9 @@ import (
 	"github.com/caraml-dev/xp/treatment-service/controller"
 	"github.com/caraml-dev/xp/treatment-service/instrumentation"
 	"github.com/caraml-dev/xp/treatment-service/models"
+	"github.com/caraml-dev/xp/treatment-service/monitoring"
 	"github.com/gojek/mlp/api/pkg/instrumentation/metrics"
+	"github.com/google/uuid"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
 
@@ -64,7 +66,9 @@ func (er *experimentRunner) GetTreatmentForRequest(
 	var treatment schema.SelectedTreatment
 	var switchbackWindowId *int64
 	var err error
+
 	statusCode := http.StatusBadRequest
+	filterParams := api.FetchTreatmentRequestBody{AdditionalProperties: requestParams}
 
 	defer func() {
 		if requestFilter == nil {
@@ -78,12 +82,65 @@ func (er *experimentRunner) GetTreatmentForRequest(
 				projectId,
 				statusCode,
 				err,
-				api.FetchTreatmentRequestBody{AdditionalProperties: requestParams},
+				filterParams,
 				requestFilter,
 			)
 		}
 	}()
 
+	var lookupRequestFilters []models.SegmentFilter
+	var errorLog *monitoring.ErrorResponseLog
+
+	if er.appContext.AssignedTreatmentLogger != nil {
+		defer func() {
+			// Capture potential errors from other calls to service layer and prevent it from
+			// slipping pass subsequent JSON marshaling errors
+			if err != nil {
+				errorLog = &monitoring.ErrorResponseLog{Code: statusCode, Error: err.Error()}
+			}
+
+			headerJson, err := json.Marshal(reqHeader)
+			if err != nil {
+				errorLog = &monitoring.ErrorResponseLog{Code: statusCode, Error: err.Error()}
+			}
+			bodyJson, err := json.Marshal(filterParams)
+			if err != nil {
+				errorLog = &monitoring.ErrorResponseLog{Code: statusCode, Error: err.Error()}
+			}
+			requestJson := &monitoring.Request{
+				Header: string(headerJson),
+				Body:   string(bodyJson),
+			}
+
+			var requestFilters []models.SegmentFilter
+			if errorLog == nil {
+				requestFilters = lookupRequestFilters
+			}
+
+			assignedTreatmentLog := &monitoring.AssignedTreatmentLog{
+				ProjectID:  projectId,
+				RequestID:  uuid.New().String(),
+				Experiment: filteredExperiment,
+				Treatment:  selectedTreatment,
+				Request:    requestJson,
+				Segmenters: requestFilters,
+			}
+			if filteredExperiment != nil {
+				assignedTreatmentLog.TreatmentMetadata = &monitoring.TreatmentMetadata{
+					ExperimentVersion:  filteredExperiment.Version,
+					ExperimentType:     string(models.ProtobufExperimentTypeToOpenAPI(filteredExperiment.Type)),
+					SwitchbackWindowId: switchbackWindowId,
+				}
+			}
+
+			if errorLog != nil {
+				assignedTreatmentLog.Error = errorLog
+			}
+
+			_ = er.appContext.AssignedTreatmentLogger.Append(assignedTreatmentLog)
+		}()
+	}
+
 	// Use the S2ID at the max configured level (most granular level) to generate the filter
 	requestFilter, err = er.appContext.SchemaService.GetRequestFilter(projectId, requestParams)
 	if err != nil {